A method and device for evaluating the performance of a satellite transmitting antenna

Abstract

The present invention discloses a method for evaluating the performance of an on-satellite transmitting antenna, the method comprising: obtaining a satellite system type; obtaining a circular beam spherical cap area of ​​a beam corresponding to a sub-satellite point and a maximum gain of the antenna at the sub-satellite point according to the satellite system type; obtaining an antenna capability factor according to the circular beam spherical cap area of ​​the beam corresponding to the sub-satellite point and the maximum gain of the antenna at the sub-satellite point; and comparing the antenna capability factors to evaluate the performance of the on-satellite transmitting antenna. The antenna capabilities of different satellite systems (including large beam satellites and spot beam high-throughput satellites) are evaluated under the same standard, and the evaluation is accurate.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and in particular to a method and device for evaluating the performance of an on-board transmitting antenna. Background Art

[0002] The downlink capacity of the satellite communication system is mainly completed by the combined action of five main parts: the on-board high-power amplifier, on-board transmitting antenna, orbital frequency resources, terminal receiving antenna, and physical layer forward baseband. Among them, the on-board transmitting antenna is used to convert the RF signal input by the high-power amplifier into a directional electromagnetic wave in space, thereby meeting the propagation capacity of the electromagnetic wave to a specific coverage area. The performance evaluation of the on-board transmitting antenna is of great significance for the analysis and evaluation of satellite-ground communication capabilities.

[0003] In recent years, with the continuous improvement of comprehensive national strength and the rapid development of satellite communications, higher and higher requirements have been put forward for satellite antennas, and a variety of new antenna technologies have also emerged. In order to meet the market demand for large-capacity and multi-target areas of satellite communications, communication satellite antennas have gone through a process from simple antennas (standard circular or elliptical beams), shaped antennas (multi-feed beamforming) to multi-beam forming high-gain antennas (shaped multi-beams). The performance evaluation of on-board transmitting antennas usually includes two types: antenna transmission gain and antenna coverage area. At present, for the performance comparison of different satellite antennas, it is usually necessary to consult the satellite technical manual and compare the EIRP or coverage area of ​​the beam. The evaluation is also inaccurate, and there is no unified standard satellite antenna evaluation method. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a method for evaluating the performance of a satellite transmitting antenna, the method comprising:

[0005] Get the satellite system type;

[0006] According to the satellite system type, obtaining a circular beam spherical cap area of ​​the beam corresponding to a sub-satellite point and a maximum gain of the antenna at the sub-satellite point;

[0007] Obtaining an antenna capability factor according to a circular beam spherical crown area of ​​the beam corresponding to a sub-satellite point and a maximum gain of the antenna at the sub-satellite point;

[0008] The antenna capability factors are compared to evaluate the performance of the onboard transmitting antenna.

[0009] Preferably, the satellite system types include large-beam satellites and spot-beam high-throughput satellites.

[0010] Preferably, if the original beam coverage of the large-beam satellite is a non-circular beam, the original beam coverage is converted into an equivalent circular beam with the same geometric factor at the sub-satellite point.

[0011] Preferably, a reduction in the antenna capability factor will reduce the performance of the antenna.

[0012] Preferably, the performance of the antenna determines the antenna gain and coverage area.

[0013] A device for evaluating the performance of a satellite transmitting antenna, the device comprising:

[0014] Satellite type module, used to obtain satellite system type;

[0015] The antenna gain module is used to obtain the circular beam spherical crown area of ​​the beam corresponding to the sub-satellite point and the maximum gain of the antenna at the sub-satellite point according to the type of the satellite system;

[0016] An antenna capability factor module, used to obtain an antenna capability factor according to a circular beam crown area of ​​a sub-satellite point corresponding to the beam and a maximum gain of the antenna at the sub-satellite point;

[0017] The evaluation module is used to compare the antenna capability factors and evaluate the performance of the onboard transmitting antenna.

[0018] Preferably, the satellite type modules include large beam satellite modules and spot beam high throughput satellite modules.

[0019] Preferably, the large-beam satellite module is used for converting the original beam coverage of the large-beam satellite into an equivalent circular beam with the same geometric factor at the sub-satellite point if the original beam coverage is a non-circular beam.

[0020] Preferably, a reduction in the antenna capability factor will reduce the performance of the antenna.

[0021] Preferably, the performance of the antenna determines the antenna gain and coverage area.

[0022] The method and device for evaluating the performance of a satellite transmitting antenna provided by the present invention have the following advantages compared with the prior art:

[0023] The present invention designs a comprehensive antenna gain G MAX And the on-board antenna performance evaluation index Q of the antenna coverage area S A This evaluation method combines the on-board transmitting antenna coverage area and antenna gain. Compared with the traditional single antenna coverage area evaluation method and antenna gain evaluation method, this evaluation method can evaluate the antenna capabilities of different satellite systems (including large-beam satellites and spot-beam high-throughput satellites) under the same standard, and thus can accurately evaluate the satellite-to-ground communication capabilities of different satellite systems under a unified framework. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1is a flowchart of a method for evaluating the performance of a satellite transmitting antenna according to an embodiment of the present invention;

[0025] Figure 2 is the change in the directional pattern of circular beams of different sizes according to an embodiment of the present invention;

[0026] Figure 3 is the antenna center gain relationship corresponding to different antenna coverage areas in the implementation scheme of the present invention;

[0027] Figure 4 is the antenna capability factor Q of different satellites according to the embodiment of the present invention A distribution relationship of

[0028] Figure 5 4 is a schematic diagram of the structure of a device for evaluating the performance of a transmitting antenna on a satellite according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] In order to clearly illustrate the scheme in the present invention, preferred embodiments are given below and described in detail with reference to the accompanying drawings. The following description is essentially only exemplary and is not intended to limit the application or use of the present disclosure. It should be understood that in all the drawings, corresponding reference numerals represent the same or corresponding parts and features.

[0030] like Figure 1 According to the implementation scheme, a method for evaluating the performance of a satellite transmitting antenna is provided, the method comprising:

[0031] S101, obtaining the satellite system type;

[0032] Specifically, satellite system types include large-beam satellites and spot-beam high-throughput satellites.

[0033] S102, according to the satellite system type, obtain the circular beam spherical crown area of ​​the beam corresponding to the sub-satellite point and the maximum gain of the antenna at the sub-satellite point; if the original beam coverage of the large-beam satellite is a non-circular beam, convert the original beam coverage into an equivalent circular beam with the same geometric factor at the sub-satellite point.

[0034] Whether it is a large-beam or spot-beam high-throughput satellite, what actually changes for the on-board antenna is only the change in the beam directivity coefficient (directional pattern), which results in a change in the coverage area. Taking a circular beam as an example, when the beam angle is of different sizes, the directivity coefficient of the antenna changes, resulting in a change in the antenna gain. Figure 2 The directional pattern changes for circular beams of different sizes.

[0035] If the beam is pointed at the sub-satellite point, the coverage area of ​​the sub-satellite point can be approximately calculated in the manner of a spherical cap (where r is the radius of the spherical cap and R is the radius of the earth):

[0036]

[0037] S103, obtaining an antenna capability factor according to a circular beam crown area of ​​a beam corresponding to a sub-satellite point and a maximum gain of the antenna at the sub-satellite point;

[0038] A reduction in the antenna capability factor will reduce the performance of the antenna.

[0039] The performance of the antenna determines the antenna gain and coverage area.

[0040] Figure 3 This is the antenna center gain relationship corresponding to different antenna coverage areas in the implementation scheme of the present invention. Figure 3 It can be seen that there is an obvious linear relationship with a slope of -1, so it can be approximately considered that the sum of the coverage area and the decibel value of the antenna gain is a constant, and the antenna capability factor Q is introduced. A as follows:

[0041] Q A =G MAX +10×log 10 S(dBkm 2 )

[0042] Where S is the spherical cap area of ​​the circular beam corresponding to the sub-satellite point. For non-circular beam systems, it is necessary to convert the coverage area into a sub-satellite circular beam using the spatial geometric factor in the PhiTheta coordinate system. G MAX is the maximum gain of the antenna at the sub-satellite point.

[0043] S104, comparing antenna capability factors and evaluating the performance of the onboard transmitting antenna.

[0044] The different satellites are compared uniformly, and the results are shown in Table 1 below:

[0045]

[0046] According to the above table, the capability factor Q of different satellite antennas can be obtained: A The distribution relationship of Figure 4 shown.

[0047] from Figure 4 It can be seen that the distribution differences of antenna capability factors corresponding to different antenna technologies are as follows:

[0048] 1) The shaped large-beam antenna technology of large-beam satellites is relatively mature, and it can be seen that the antenna capability factor is high;

[0049] 2) The three-aperture multi-beam technology of high-throughput satellites is relatively mature, and the antenna capability factor is slightly lower than that of shaped large-beam antenna technology;

[0050] 3) The shaped multi-beam technology of high-throughput satellites will cause a certain performance degradation, and the average value of the antenna capability factor is slightly lower than that of the three-aperture multi-beam technology;

[0051] 4) The performance of the four-feed multi-beam technology of high-throughput satellites has declined significantly, and the average antenna capability factor is significantly lower than the above three antenna technologies.

[0052] Based on this satellite antenna performance evaluation method, it can further provide certain guidance for the satellite-ground link performance evaluation. The decrease in antenna capability factor will directly affect the performance of the antenna. Taking a decrease of 3dB as an example, if the same antenna performance and antenna gain performance need to be guaranteed, its coverage area needs to be reduced by about 50%, or under the condition of the same coverage area, the antenna performance of the beam decreases by 50%. In the downlink direction, the power spectrum density can be improved by reducing the antenna gain capability by 50% to achieve the same communication signal-to-noise ratio, but a 50% decrease in the signal-to-noise ratio performance in the uplink direction will be inevitable.

[0053] like Figure 5 As shown, the embodiment provides a device for evaluating the performance of a transmitting antenna on a satellite, the device comprising:

[0054] The satellite type module 201 is used to obtain the satellite system type; the satellite type module includes a large beam satellite module and a spot beam high throughput satellite module. The large beam satellite module is used to convert the original beam coverage of the large beam satellite into an equivalent circular beam with the same geometric factor at the sub-satellite point if the original beam coverage is a non-circular beam.

[0055] The antenna gain module 202 is used to obtain the circular beam crown area of ​​the beam corresponding to the sub-satellite point and the maximum gain of the antenna at the sub-satellite point according to the satellite system type; the reduction of the antenna capability factor will reduce the performance of the antenna. The performance of the antenna determines the antenna gain and coverage area.

[0056] The antenna capability factor module 203 is used to obtain the antenna capability factor according to the circular beam crown area corresponding to the sub-satellite point and the maximum gain of the antenna at the sub-satellite point; the evaluation module 204 is used to compare the antenna capability factors and evaluate the performance of the on-board transmitting antenna.

[0057] In summary, the above contents are only embodiments of the present invention, which are only used to illustrate the principles of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for evaluating the performance of a satellite transmitting antenna, characterized in that: The method includes: Get the satellite system type; According to the satellite system type, obtaining a circular beam spherical cap area of ​​the beam corresponding to a sub-satellite point and a maximum gain of the antenna at the sub-satellite point; Obtaining an antenna capability factor according to a circular beam spherical crown area of ​​the beam corresponding to a sub-satellite point and a maximum gain of the antenna at the sub-satellite point; Compare the antenna capability factors to evaluate the performance of the onboard transmitting antenna: Wherein, the satellite system types include large beam satellites and spot beam high throughput satellites; Among them, the antenna capability factor Q A The calculation formula is as follows: Q A =G MAX +10×log 10 S(dBkm 2 ), G MAX is the maximum gain of the antenna at the sub-satellite point, S is the circular beam crown area of ​​the beam corresponding to the sub-satellite point, dBkm 2 It is a unit that expresses the absolute value of area, with 1km 2 The area is used as the basis, and the calculation formula is dBkm 2 =10×lg(S / 1km 2 ).

2. The method for evaluating the performance of a satellite transmitting antenna according to claim 1, wherein: If the original beam of the large-beam satellite is a non-circular beam, the original beam coverage is converted into an equivalent circular beam with the same geometric factor at the sub-satellite point.

3. A device for evaluating the performance of a satellite transmitting antenna, characterized in that: The device includes: Satellite type module, used to obtain satellite system type; An antenna gain module, used for obtaining the circular beam spherical crown area of ​​the beam corresponding to the sub-satellite point and the maximum gain of the antenna at the sub-satellite point according to the type of the satellite system; An antenna capability factor module, used to obtain an antenna capability factor according to a circular beam spherical crown area of ​​the beam corresponding to a sub-satellite point and a maximum gain of the antenna at the sub-satellite point; An evaluation module, used to compare the antenna capability factors and evaluate the performance of the onboard transmitting antenna; Wherein, the satellite system types include large beam satellites and spot beam high throughput satellites; Among them, the antenna capability factor Q A The calculation formula is as follows: Q A =G MAX +10×log 10 S(dBkm 2 ), G MAX is the maximum gain of the antenna at the sub-satellite point, S is the circular beam crown area of ​​the beam corresponding to the sub-satellite point, dBkm 2 It is a unit that expresses the absolute value of area, with 1km 2 The area is used as the basis, and the calculation formula is dBkm 2 =10×lg(S / 1km 2 ).

4. The device for evaluating the performance of a satellite transmitting antenna according to claim 3, characterized in that: If the original beam of the large-beam satellite is a non-circular beam, the original beam coverage is converted into an equivalent circular beam with the same geometric factor at the sub-satellite point.

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